1. Field of the Invention
This invention relates to a small, personal watercraft powered by a jet propulsion system. More particularly, this invention relates to a control system for a bilge pump in such a watercraft.
2. Discussion of Related Art
A personal size watercraft, designed primarily for one to three riders, typically utilizes a jet propulsion system powered by an internal combustion engine. The engine crankshaft is coupled directly to the driveshaft of the jet device, so that the jet pump impeller functions whenever the engine is running. The vessel is propelled in a forward direction through drawing water into a chamber on the underside of the hull and forcefully exhausting the water in a rearward direction by the jet propulsion device. In normal use, the operator sits on a bench-type seat positioned centrally on the watercraft, and steers the vessel by means of handlebars which control the direction of flow of jet-propelled water from the stern.
Owing to the small size of the vessel, desired operating characteristics are highly dependent upon proper weight distribution. Thus, continuous removal of any water that enters the bilge area is critical to efficient operation. Existing personal watercraft are equipped with a bilge pump that pumps continuously whenever the engine is running. In this way, water cannot accumulate within the bilge and thus cannot adversely affect the weight distribution.
This dedicated use of the bilge pump, while essential to the normal operation of the vessel, has several distinct disadvantages in other situations. For example, when the vessel is at shore, starting the engine may not be a desirable or convenient means to pump out the bilge. Or when the vessel is stationary at some remote location, as when used for fishing, the operator may not wish to start the engine in order to activate the bilge pump.
Personal watercraft have been equipped with a drain plug to drain water from the bilge without starting the engine. This draining procedure involves elevating the bow of the vessel so that water may drain from the drain plug near the stern. In each of the situations described above, such a draining procedure would be difficult or impossible. An additional disadvantage of the drain plug is that the bilge may fill with water if that drain plug is not securely replaced prior to starting the engine.
A principal object of this invention, therefore, is to overcome the difficulties noted above, while retaining the salutary features of the existing bilge pump systems and assuring the safe control of the vessel.